The present invention relates to a photo sensor integrated circuit in which light is received by a light receiving element (e.g., photo diode) and is converted into photoelectric current by a photoelectric transfer device. The photoelectric current is then processed in a signal processing circuit (e.g., transistors). The photoelectric transfer device and the signal processing circuit are integrated as one chip semiconductor component.
FIG. 15 shows a conventional photo sensor integrated circuit providing a shielding film 51 on the circuit element (NPN transistor) 50 to eliminate malfunction of the circuit which may be induced by incoming light (refer to Unexamined Japanese Patent Application No. 63-116458, published in 1988).
However, this kind of photo sensor has a possibility of causing malfunction when subjected to strong light equivalent to the solar radiations because the solar radiations usually produce photo carriers which flow as current in the vicinity of the circuit element.